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fada2fcd TK |
1 | #include <stdio.h> |
2 | #include <stdlib.h> | |
3 | #include <string.h> | |
4 | #include <limits.h> | |
5 | #include <errno.h> | |
6 | #include <assert.h> | |
a1554f65 SB |
7 | #include <fcntl.h> |
8 | #include <unistd.h> | |
fada2fcd | 9 | |
634bd210 RP |
10 | #include "strntol.h" |
11 | #include "pattern.h" | |
fada2fcd | 12 | #include "../minmax.h" |
a328eb9a | 13 | #include "../oslib/strcasestr.h" |
b29c71c4 | 14 | #include "../oslib/strndup.h" |
634bd210 | 15 | |
a1554f65 SB |
16 | /** |
17 | * parse_file() - parses binary file to fill buffer | |
18 | * @beg - string input, extract filename from this | |
19 | * @out - output buffer where parsed number should be put | |
20 | * @out_len - length of the output buffer | |
21 | * @filled - pointer where number of bytes successfully | |
22 | * parsed will be put | |
23 | * | |
24 | * Returns the end pointer where parsing has been stopped. | |
25 | * In case of parsing error or lack of bytes in output buffer | |
26 | * NULL will be returned. | |
27 | */ | |
28 | static const char *parse_file(const char *beg, char *out, | |
29 | unsigned int out_len, | |
30 | unsigned int *filled) | |
31 | { | |
32 | const char *end; | |
33 | char *file; | |
34 | int fd; | |
35 | ssize_t count; | |
36 | ||
37 | if (!out_len) | |
38 | goto err_out; | |
39 | ||
40 | assert(*beg == '\''); | |
41 | beg++; | |
42 | end = strchr(beg, '\''); | |
43 | if (!end) | |
44 | goto err_out; | |
45 | ||
46 | file = strndup(beg, end - beg); | |
47 | if (file == NULL) | |
48 | goto err_out; | |
49 | ||
50 | fd = open(file, O_RDONLY); | |
51 | if (fd < 0) | |
52 | goto err_free_out; | |
53 | ||
54 | count = read(fd, out, out_len); | |
55 | if (count == -1) | |
56 | goto err_free_close_out; | |
57 | ||
58 | *filled = count; | |
59 | close(fd); | |
60 | free(file); | |
61 | ||
62 | /* Catch up quote */ | |
63 | return end + 1; | |
64 | ||
65 | err_free_close_out: | |
66 | close(fd); | |
67 | err_free_out: | |
68 | free(file); | |
69 | err_out: | |
70 | return NULL; | |
71 | ||
72 | } | |
73 | ||
634bd210 RP |
74 | /** |
75 | * parse_string() - parses string in double quotes, like "abc" | |
76 | * @beg - string input | |
77 | * @out - output buffer where parsed number should be put | |
78 | * @out_len - length of the output buffer | |
79 | * @filled - pointer where number of bytes successfully | |
80 | * parsed will be put | |
81 | * | |
82 | * Returns the end pointer where parsing has been stopped. | |
83 | * In case of parsing error or lack of bytes in output buffer | |
84 | * NULL will be returned. | |
85 | */ | |
86 | static const char *parse_string(const char *beg, char *out, | |
87 | unsigned int out_len, | |
88 | unsigned int *filled) | |
89 | { | |
90 | const char *end; | |
91 | ||
92 | if (!out_len) | |
93 | return NULL; | |
94 | ||
95 | assert(*beg == '"'); | |
96 | beg++; | |
97 | end = strchr(beg, '"'); | |
98 | if (!end) | |
99 | return NULL; | |
100 | if (end - beg > out_len) | |
101 | return NULL; | |
102 | ||
103 | memcpy(out, beg, end - beg); | |
104 | *filled = end - beg; | |
105 | ||
106 | /* Catch up quote */ | |
107 | return end + 1; | |
108 | } | |
109 | ||
110 | /** | |
111 | * parse_number() - parses numbers | |
112 | * @beg - string input | |
113 | * @out - output buffer where parsed number should be put | |
114 | * @out_len - length of the output buffer | |
115 | * @filled - pointer where number of bytes successfully | |
116 | * parsed will be put | |
117 | * | |
118 | * Supports decimals in the range [INT_MIN, INT_MAX] and | |
119 | * hexidecimals of any size, which should be started with | |
120 | * prefix 0x or 0X. | |
121 | * | |
122 | * Returns the end pointer where parsing has been stopped. | |
123 | * In case of parsing error or lack of bytes in output buffer | |
124 | * NULL will be returned. | |
125 | */ | |
126 | static const char *parse_number(const char *beg, char *out, | |
127 | unsigned int out_len, | |
128 | unsigned int *filled) | |
129 | { | |
130 | const char *end; | |
131 | unsigned int val; | |
132 | long lval; | |
133 | int num, i; | |
134 | ||
135 | if (!out_len) | |
136 | return NULL; | |
137 | ||
138 | num = 0; | |
139 | sscanf(beg, "0%*[xX]%*[0-9a-fA-F]%n", &num); | |
140 | if (num == 0) { | |
141 | /* Here we are trying to parse decimal */ | |
142 | ||
143 | char *_end; | |
144 | ||
145 | /* Looking ahead */ | |
146 | _end = strcasestr(beg, "0x"); | |
147 | if (_end) | |
148 | num = _end - beg; | |
149 | if (num) | |
150 | lval = strntol(beg, num, &_end, 10); | |
151 | else | |
152 | lval = strtol(beg, &_end, 10); | |
153 | if (beg == _end || lval > INT_MAX || lval < INT_MIN) | |
154 | return NULL; | |
155 | end = _end; | |
156 | i = 0; | |
157 | if (!lval) { | |
158 | num = 0; | |
159 | out[i] = 0x00; | |
160 | i = 1; | |
161 | } else { | |
162 | val = (unsigned int)lval; | |
163 | for (; val && out_len; out_len--, i++, val >>= 8) | |
164 | out[i] = val & 0xff; | |
165 | if (val) | |
166 | return NULL; | |
167 | } | |
168 | } else { | |
169 | assert(num > 2); | |
170 | ||
171 | /* Catch up 0x prefix */ | |
172 | num -= 2; | |
173 | beg += 2; | |
174 | ||
175 | /* Look back, handle this combined string: 0xff0x14 */ | |
176 | if (beg[num] && !strncasecmp(&beg[num - 1], "0x", 2)) | |
177 | num--; | |
178 | ||
179 | end = beg + num; | |
180 | ||
181 | for (i = 0; num && out_len; | |
182 | out_len--, i++, num -= 2, beg += 2) { | |
183 | const char *fmt; | |
184 | ||
185 | fmt = (num & 1 ? "%1hhx" : "%2hhx"); | |
186 | sscanf(beg, fmt, &out[i]); | |
187 | if (num & 1) { | |
188 | num++; | |
189 | beg--; | |
190 | } | |
191 | } | |
192 | if (num) | |
193 | return NULL; | |
194 | } | |
195 | ||
196 | *filled = i; | |
197 | return end; | |
198 | ||
199 | } | |
200 | ||
201 | /** | |
202 | * parse_format() - parses formats, like %o, etc | |
203 | * @in - string input | |
204 | * @out - output buffer where space for format should be reserved | |
205 | * @parsed - number of bytes which were already parsed so far | |
206 | * @out_len - length of the output buffer | |
44031abf | 207 | * @fmt_desc - format descriptor array, what we expect to find |
634bd210 RP |
208 | * @fmt - format array, the output |
209 | * @fmt_sz - size of format array | |
210 | * | |
211 | * This function tries to find formats, e.g.: | |
212 | * %o - offset of the block | |
213 | * | |
fc002f14 | 214 | * In case of successful parsing it fills the format param |
634bd210 RP |
215 | * with proper offset and the size of the expected value, which |
216 | * should be pasted into buffer using the format 'func' callback. | |
217 | * | |
218 | * Returns the end pointer where parsing has been stopped. | |
219 | * In case of parsing error or lack of bytes in output buffer | |
220 | * NULL will be returned. | |
221 | */ | |
222 | static const char *parse_format(const char *in, char *out, unsigned int parsed, | |
223 | unsigned int out_len, unsigned int *filled, | |
224 | const struct pattern_fmt_desc *fmt_desc, | |
634bd210 RP |
225 | struct pattern_fmt *fmt, unsigned int fmt_sz) |
226 | { | |
227 | int i; | |
228 | struct pattern_fmt *f = NULL; | |
229 | unsigned int len = 0; | |
230 | ||
969b9fbb | 231 | if (!out_len || !fmt_desc || !fmt || !fmt_sz) |
634bd210 RP |
232 | return NULL; |
233 | ||
234 | assert(*in == '%'); | |
235 | ||
969b9fbb | 236 | for (i = 0; fmt_desc[i].fmt; i++) { |
634bd210 RP |
237 | const struct pattern_fmt_desc *desc; |
238 | ||
239 | desc = &fmt_desc[i]; | |
240 | len = strlen(desc->fmt); | |
241 | if (0 == strncmp(in, desc->fmt, len)) { | |
242 | fmt->desc = desc; | |
243 | fmt->off = parsed; | |
244 | f = fmt; | |
245 | break; | |
246 | } | |
247 | } | |
248 | ||
249 | if (!f) | |
250 | return NULL; | |
251 | if (f->desc->len > out_len) | |
252 | return NULL; | |
253 | ||
254 | memset(out, '\0', f->desc->len); | |
255 | *filled = f->desc->len; | |
256 | ||
257 | return in + len; | |
258 | } | |
259 | ||
260 | /** | |
261 | * parse_and_fill_pattern() - Parses combined input, which consists of strings, | |
262 | * numbers and pattern formats. | |
263 | * @in - string input | |
264 | * @in_len - size of the input string | |
265 | * @out - output buffer where parsed result will be put | |
266 | * @out_len - lengths of the output buffer | |
267 | * @fmt_desc - array of pattern format descriptors [input] | |
634bd210 RP |
268 | * @fmt - array of pattern formats [output] |
269 | * @fmt_sz - pointer where the size of pattern formats array stored [input], | |
fc002f14 | 270 | * after successful parsing this pointer will contain the number |
634bd210 RP |
271 | * of parsed formats if any [output]. |
272 | * | |
273 | * strings: | |
274 | * bytes sequence in double quotes, e.g. "123". | |
275 | * NOTE: there is no way to escape quote, so "123\"abc" does not work. | |
276 | * | |
277 | * numbers: | |
fc002f14 | 278 | * hexadecimal - sequence of hex bytes starting from 0x or 0X prefix, |
634bd210 RP |
279 | * e.g. 0xff12ceff1100ff |
280 | * decimal - decimal number in range [INT_MIN, INT_MAX] | |
281 | * | |
282 | * formats: | |
283 | * %o - offset of block, reserved 8 bytes. | |
284 | * | |
285 | * Explicit examples of combined string: | |
286 | * #1 #2 #3 #4 | |
287 | * in="abcd" in=-1024 in=66 in=0xFF0X1 | |
288 | * out=61 62 63 64 out=00 fc ff ff out=42 out=ff 01 | |
289 | * | |
290 | * #5 #6 | |
291 | * in=%o in="123"0xFFeeCC | |
292 | * out=00 00 00 00 00 00 00 00 out=31 32 33 ff ec cc | |
293 | * | |
294 | * #7 | |
295 | * in=-100xab"1"%o"2" | |
296 | * out=f6 ff ff ff ab 31 00 00 00 00 00 00 00 00 32 | |
297 | * | |
298 | * #9 | |
299 | * in=%o0xdeadbeef%o | |
300 | * out=00 00 00 00 00 00 00 00 de ad be ef 00 00 00 00 00 00 00 00 | |
301 | * | |
302 | * #10 | |
303 | * in=0xfefefefefefefefefefefefefefefefefefefefefe | |
304 | * out=fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe | |
305 | * | |
306 | * Returns number of bytes filled or err < 0 in case of failure. | |
307 | */ | |
308 | int parse_and_fill_pattern(const char *in, unsigned int in_len, | |
309 | char *out, unsigned int out_len, | |
310 | const struct pattern_fmt_desc *fmt_desc, | |
634bd210 RP |
311 | struct pattern_fmt *fmt, |
312 | unsigned int *fmt_sz_out) | |
313 | { | |
314 | const char *beg, *end, *out_beg = out; | |
315 | unsigned int total = 0, fmt_rem = 0; | |
316 | ||
317 | if (!in || !in_len || !out || !out_len) | |
318 | return -EINVAL; | |
319 | if (fmt_sz_out) | |
320 | fmt_rem = *fmt_sz_out; | |
321 | ||
322 | beg = in; | |
323 | do { | |
324 | unsigned int filled; | |
325 | int parsed_fmt; | |
326 | ||
327 | filled = 0; | |
328 | parsed_fmt = 0; | |
329 | ||
330 | switch (*beg) { | |
a1554f65 SB |
331 | case '\'': |
332 | end = parse_file(beg, out, out_len, &filled); | |
333 | break; | |
634bd210 RP |
334 | case '"': |
335 | end = parse_string(beg, out, out_len, &filled); | |
336 | break; | |
337 | case '%': | |
338 | end = parse_format(beg, out, out - out_beg, out_len, | |
969b9fbb | 339 | &filled, fmt_desc, fmt, fmt_rem); |
634bd210 RP |
340 | parsed_fmt = 1; |
341 | break; | |
342 | default: | |
343 | end = parse_number(beg, out, out_len, &filled); | |
344 | break; | |
345 | } | |
346 | ||
347 | if (!end) | |
348 | return -EINVAL; | |
349 | ||
350 | if (parsed_fmt) { | |
351 | assert(fmt_rem); | |
352 | fmt_rem--; | |
353 | fmt++; | |
354 | } | |
355 | ||
356 | assert(end - beg <= in_len); | |
357 | in_len -= end - beg; | |
358 | beg = end; | |
359 | ||
360 | assert(filled); | |
361 | assert(filled <= out_len); | |
362 | out_len -= filled; | |
363 | out += filled; | |
364 | total += filled; | |
365 | ||
366 | } while (in_len); | |
367 | ||
368 | if (fmt_sz_out) | |
369 | *fmt_sz_out -= fmt_rem; | |
370 | return total; | |
371 | } | |
372 | ||
373 | /** | |
374 | * dup_pattern() - Duplicates part of the pattern all over the buffer. | |
375 | * | |
376 | * Returns 0 in case of success or errno < 0 in case of failure. | |
377 | */ | |
378 | static int dup_pattern(char *out, unsigned int out_len, unsigned int pattern_len) | |
379 | { | |
380 | unsigned int left, len, off; | |
381 | ||
382 | if (out_len <= pattern_len) | |
383 | /* Normal case */ | |
384 | return 0; | |
385 | ||
386 | off = pattern_len; | |
387 | left = (out_len - off); | |
388 | len = min(left, off); | |
389 | ||
390 | /* Duplicate leftover */ | |
391 | while (left) { | |
392 | memcpy(out + off, out, len); | |
393 | left -= len; | |
394 | off <<= 1; | |
395 | len = min(left, off); | |
396 | } | |
397 | ||
398 | return 0; | |
399 | } | |
400 | ||
401 | /** | |
402 | * cpy_pattern() - Copies pattern to the buffer. | |
403 | * | |
404 | * Function copies pattern along the whole buffer. | |
405 | * | |
406 | * Returns 0 in case of success or errno < 0 in case of failure. | |
407 | */ | |
408 | int cpy_pattern(const char *pattern, unsigned int pattern_len, | |
409 | char *out, unsigned int out_len) | |
410 | { | |
411 | unsigned int len; | |
412 | ||
413 | if (!pattern || !pattern_len || !out || !out_len) | |
414 | return -EINVAL; | |
415 | ||
416 | /* Copy pattern */ | |
417 | len = min(pattern_len, out_len); | |
418 | memcpy(out, pattern, len); | |
419 | ||
420 | /* Spread filled chunk all over the buffer */ | |
421 | return dup_pattern(out, out_len, pattern_len); | |
422 | } | |
423 | ||
424 | /** | |
425 | * cmp_pattern() - Compares pattern and buffer. | |
426 | * | |
427 | * For the sake of performance this function avoids any loops. | |
428 | * Firstly it tries to compare the buffer itself, checking that | |
429 | * buffer consists of repeating patterns along the buffer size. | |
430 | * | |
431 | * If the difference is not found then the function tries to compare | |
432 | * buffer and pattern. | |
433 | * | |
434 | * Returns 0 in case of success or errno < 0 in case of failure. | |
435 | */ | |
436 | int cmp_pattern(const char *pattern, unsigned int pattern_size, | |
437 | unsigned int off, const char *buf, unsigned int len) | |
438 | { | |
439 | int rc; | |
440 | unsigned int size; | |
441 | ||
442 | /* Find the difference in buffer */ | |
443 | if (len > pattern_size) { | |
444 | rc = memcmp(buf, buf + pattern_size, len - pattern_size); | |
445 | if (rc) | |
446 | return -EILSEQ; | |
447 | } | |
448 | /* Compare second part of the pattern with buffer */ | |
449 | if (off) { | |
450 | size = min(len, pattern_size - off); | |
451 | rc = memcmp(buf, pattern + off, size); | |
452 | if (rc) | |
453 | return -EILSEQ; | |
454 | buf += size; | |
455 | len -= size; | |
456 | } | |
457 | /* Compare first part of the pattern or the whole pattern | |
458 | * with buffer */ | |
459 | if (len) { | |
460 | size = min(len, (off ? off : pattern_size)); | |
461 | rc = memcmp(buf, pattern, size); | |
462 | if (rc) | |
463 | return -EILSEQ; | |
464 | } | |
465 | ||
466 | return 0; | |
467 | } | |
468 | ||
469 | /** | |
470 | * paste_format_inplace() - Pastes parsed formats to the pattern. | |
471 | * | |
472 | * This function pastes formats to the pattern. If @fmt_sz is 0 | |
473 | * function does nothing and pattern buffer is left untouched. | |
474 | * | |
475 | * Returns 0 in case of success or errno < 0 in case of failure. | |
476 | */ | |
477 | int paste_format_inplace(char *pattern, unsigned int pattern_len, | |
478 | struct pattern_fmt *fmt, unsigned int fmt_sz, | |
479 | void *priv) | |
480 | { | |
481 | int i, rc; | |
482 | unsigned int len; | |
483 | ||
484 | if (!pattern || !pattern_len || !fmt) | |
485 | return -EINVAL; | |
486 | ||
487 | /* Paste formats for first pattern chunk */ | |
488 | for (i = 0; i < fmt_sz; i++) { | |
489 | struct pattern_fmt *f; | |
490 | ||
491 | f = &fmt[i]; | |
492 | if (pattern_len <= f->off) | |
493 | break; | |
494 | len = min(pattern_len - f->off, f->desc->len); | |
495 | rc = f->desc->paste(pattern + f->off, len, priv); | |
496 | if (rc) | |
497 | return rc; | |
498 | } | |
499 | ||
500 | return 0; | |
501 | } | |
502 | ||
503 | /** | |
504 | * paste_format() - Pastes parsed formats to the buffer. | |
505 | * | |
506 | * This function copies pattern to the buffer, pastes format | |
507 | * into it and then duplicates pattern all over the buffer size. | |
508 | * | |
509 | * Returns 0 in case of success or errno < 0 in case of failure. | |
510 | */ | |
511 | int paste_format(const char *pattern, unsigned int pattern_len, | |
512 | struct pattern_fmt *fmt, unsigned int fmt_sz, | |
513 | char *out, unsigned int out_len, void *priv) | |
514 | { | |
515 | int rc; | |
516 | unsigned int len; | |
517 | ||
518 | if (!pattern || !pattern_len || !out || !out_len) | |
519 | return -EINVAL; | |
520 | ||
521 | /* Copy pattern */ | |
522 | len = min(pattern_len, out_len); | |
523 | memcpy(out, pattern, len); | |
524 | ||
525 | rc = paste_format_inplace(out, len, fmt, fmt_sz, priv); | |
526 | if (rc) | |
527 | return rc; | |
528 | ||
529 | /* Spread filled chunk all over the buffer */ | |
530 | return dup_pattern(out, out_len, pattern_len); | |
531 | } |